11.4.2 Water ingress
With the pressure control valves shut, a large build-up of condensation will occur in the steam lines. If this condensation were allowed to remain, water would be passed through the system when the valves are opened, resulting in damage to the valves and condenser.
To avoid this build-up, drains are located at strategic positions, for example, in the busmain and upstream of each control valve shown in Fig 2.85. Drains are also present on the HP system of the fossil-fired plant shown in Fig 2.86 to prevent ingress of water from the spray water system.